minor #3599 [CHANGELOG] fix reference to contributing docs (xabbuh)

This PR was merged into the 2.3 branch.

Discussion
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[CHANGELOG] fix reference to contributing docs

| Q             | A
| ------------- | ---
| Doc fix?      | yes
| New docs?     | no
| Applies to    | all
| Fixed tickets |

Commits
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8a19460 fix reference to contributing docs

changelog.rst

@@ -11,7 +11,7 @@ documentation.
 .. tip::
 
     Do you also want to participate in the Symfony Documentation? Take a look
-    at the ":doc:`/contributing/documentation`" article.
+    at the ":doc:`/contributing/documentation/overview`" article.
 
 January, 2014
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